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Eating Disorders Genetics Initiative (EDGI)

Decades of research have established that there is a genetic element to the development of eating disorders. In fact, twin studies have shown that eating disorders are 1.5 times more heritable than depression, with just over half of the risk a result of complex genetic factors. However, EDGI now wants to uncover exactly which genes are responsible. This is where you come in!

What is EDGI?

The Eating Disorders Genetics Initiative (EDGI) is the UK’s largest ever genetic research project into eating disorders. The aim is to collect the psychological, medical, and genetic information of 10,000 people with experience of any eating disorder. This will help us to better understand the role our genes and environment play on the development and treatment of these illnesses. EDGI is part of an international collaboration, with many countries coming together as part of the same initiative.

How can I get involved?

We can only reach our goal with your support – we need thousands of participants to contribute to this cause. Every single person counts. You can sign up or get more information on their website.

There are four steps to joining EDGI*:

  1. Register through the website and read the information sheet
  2. Provide consent
  3. Complete a ~30 minute questionnaire to see if you are eligible
  4. Once received, complete your saliva DNA kit and return via post

*Please note you do not need to have received a diagnosis or treatment in order to take part, and you do not need to tell your healthcare provider (all your information is confidential and packaging is discreet and free)

What are the wider implications of EDGI?

A deeper understanding of eating disorders means we will be better equipped to help those who are experiencing these illnesses. EDGI is also an important information resource that enables the efficient recontacting of volunteers for further research. For too long, eating disorders have been stigmatised by society, underrepresented in mental health research, and overlooked by research funding bodies. Together with your help, we want to change this.

What are the latest findings?

Eating disorders are just as likely to start in adulthood as childhood, new EDGI report finds

In October 2021, EDGI released a new report which found that eating disorders are just as likely to start in adulthood as childhood. Specifically, over half of people with eating disorders first experience symptoms of binge eating or low weight as adults, while over 39% of people first recognise bulimia symptoms over the age of 18.

You can read the full 'Age of Onset' report here.

Frequently Asked Questions

If eating disorders are genetic, are mental illnesses too?

Yes, mental illnesses are both environmentally and genetically influenced. How much is a result of genetics varies by disorder and ranges from 35-40% for depression and anxiety disorders to up to 80%, such as for ADHD, schizophrenia, and bipolar disorder (Pettersson et al., 2017). This has been established through twin and genetic studies. However, it is important to remember that genetic effects sum together with environmental risks - heritability just represents the proportion of the risk of developing something that is genetic and a family history of a psychiatric disorder actually only represents a small increase in absolute risk of developing one.

Can different eating disorders be linked to different genes? Or is it simply that a person is more genetically predisposed to suffer from any sort of eating disorder?

In terms of molecular genetic studies (i.e., looking specifically at which genes are involved), the only disorder that has been studied in this way is Anorexia Nervosa. Therefore, we cannot know (yet) whether the same genes that are involved in the development of Anorexia are also involved in the development of other eating disorders, such as Purging Disorder. It makes intuitive sense, however, that eating disorders with overlapping symptoms (such as Binge-Eating Disorder and Bulimia Nervosa) might show strong genetic correlations. With EDGI, we hope to find out more about this.

What is the link between genetics and pro ana?

To our knowledge, there have been no studies looking at the connection between genetics and tendency to view pro ana content.

Is there a reason the study is England only?

Due to our ethics and current funding, we are only able to recruit in England for the time being. We hope that in the near future we will be able to expand to the rest of the UK. Eating disorders deserve a lot more attention in government initiatives. Write to your local MP to demand for increased funding to eating disorder research!

With BED, is the early stage research suggesting any similarities with the genetic trends seen in people more likely to develop addictions to things like alcohol/drugs?

Research has found that substance-abuse disorder and Binge-Eating Disorder can co-occur (Schreiber, 2013), but the genetic aspect of this has yet to be explored. Some research has suggested that substance abuse and eating disorders are associated due to shared risk factors such as social isolation, low self-esteem, comorbid mental health disorders, and brain chemistry (Harrop et al., 2009).

What about other comorbidities?

Different eating disorders co-occur with different disorders. For example, Anorexia more commonly co-occurs with Obsessive-Compulsive Disorder than binge-type eating disorders (Mandelli et al., 2020), whilst Binge-Eating Disorder more commonly co-occurs with ADHD and substance misuse disorders than restrictive-type eating disorders (Reinblatt, 2015). However, comorbid mood disorders such as anxiety and depression are common across many eating disorders.

Can you explain the metabolic genetic element a bit more?

Anorexia Nervosa has long been seen as a psychiatric condition. However, research published by the creators of EDGI found that the genetic factors that are associated with Anorexia influence physical activity and overlaps with metabolic (including glycemic, lipids and body measurements) that are not due to genetic effects that influence the BMI. For a full overview, we recommend reading the blog post written by the lead of EDGI in the USA.

My birth parents were drug addicts [I’m adopted]. Does this play a part in my eating disorder?

Genetics play a role in the majority of health conditions, however so does the environment. It is important to remember that having a high genetic predisposition to a mental health disorder does not, by any means, translate to a 100% chance that you will develop it - your lifetime risk of developing a disorder might increase from 1 to 3% in absolute terms, for example. There are strong indications that some disorders have large “gene-environment correlations” that amplify heritability estimates. This is confirmed by adoption studies that indicate that risk is lower for adoptees than for children who remain with birth parents for some but not all disorders but are likely to apply to drug use in particular. In simple terms, having a high genetic load for a disorder means that you require fewer environmental risk factors to go on to experience a disorder, compared to someone with a lower genetic load. However, whilst you cannot change your genetic makeup, you can seek out protective factors (e.g., social support, a healthy sleep pattern), which can act as a buffer to you developing mental ill health, even if you do go on to have some difficult experiences (e.g., trauma).

Does the research include looking at if different ED types are genetically related / similar / totally distinct?

Yes, this is one of the aims of the study - to look at how different eating disorders are genetically related or if they are completely distinct from each other. Most of the current studies on eating disorders, particularly in genetics, have focused on Anorexia Nervosa. We are looking to recruit more people with eating disorders such as Bulimia Nervosa and Binge-Eating Disorder in order to better understand the genetic underpinnings of these conditions.

Have you learned about ARFID in the research?

Whilst ARFID is a common eating disorder, particularly in children, it is under researched. At EDGI, we are recruiting those who have experienced ARFID, whether that’s in the past or currently, regardless of whether a diagnosis has been received. To learn more about genetics specifically, we will need a large number of people to participate and donate their genetic data. We are excited about the research that this will enable.

Can you take part if you’re in recovery?

Absolutely! EDGI is recruiting anyone who has ever experienced any eating disorder, whether this is in the past or something you are currently experiencing. You do need to have received a diagnosis or treatment to take part, however you must be over the age of 16 and live in England. Sign up through our website at edgiuk.org. After you complete our online sign-up survey, if you are eligible, we will send you a DNA saliva kit for you to send back to us.

Are women more genetically susceptible? Or is that a clinical bias and stigma for treatment?

Whilst it is more common for women to develop eating disorders such as Anorexia Nervosa, eating disorders can occur in any sex or gender. There are metabolic genetics that differ in women compared to men, e.g. the genetics of body composition, and the combination of increased environmental sensitivity seen in women, experiences of trauma, and their biochemistry, all could make them more susceptible (Hübel et al., 2019).

How much can you attribute a factor to genetics as opposed to a parent showing signs of an eating disorder which a child picks up?

It is a difficult task to disentangle the influence of the environment from that of genetics. When genetically influenced traits in parents (e.g., genetic predisposition to an eating disorder) influences the environment a child is in (e.g., a parent showing signs of an eating disorder), this results in what is known as ‘passive gene-environment correlation’. We are able to work through this complex question through different methods, such as twin studies and genome-wide association studies (GWAS). Twin studies observe how often a set of identical twins (sharing 100% DNA) compared to fraternal twins (sharing 50% of their DNA) have the same condition in order to identify how heritable a trait, or disorder is. A GWAS involves looking at thousands of people’s complete sets of DNA (which all have a particular condition), and detecting common genetic variations.